202 INSECTS AFFECTING VEGETATION 



gests burning stems and hulls after hulling and the destruction of all 

 outstanding clover heads, as a remedy worth trying. 



Clover-Seed Midge. When we consider the large amount of 

 clover seed, the depredations of the tiny seed midge become of alarm- 

 ing importance. So small and frail is this creature that one almost 

 doubts its ability to injure anything. Nevertheless, most of the fail- 

 ure of June clover and mammoth clover to seed is due to it, and pos- 

 sibly to the clover-seed chalcid with which it is sometimes confused. 

 The life-history of this creature is well known, and fortunately we 

 are able to so time our cutting as to take advantage of the creature 

 and thus secure a crop of seed most of the time. A brief review of 

 the life-history is as follows: 



The light-yellow eggs are laid just inside the flower tubes at the 

 time when they are beginning to show color. After a short time the 

 eggs turn red in color, hatch, and each one produces a tiny maggot 

 which travels down inside its flower tube to attack the soft seed 

 forming at its base. This seed is known as the ovule at this stage, 

 and it furnishes just the right sort of food for the maggot when 

 in this soft condition. Later, when the ovules commence to get 

 hard, they are safe from attack since the mouth parts of the maggot 

 are feeble. 



In the ordinary course of events, when the first crop of clover 

 is cut late, the maggots descend to the ground, bury themselves, and 

 change to puparia, which stage corresponds to the cocoon stage of 

 moths, later they transform to minute flies, much smaller than mos- 

 quitoes, which are just in time to lay their eggs in the coloring 

 clover-blossoms of the second crop. These if undisturbed reach the 

 pupal stage by winter, in which condition they remain until spring, 

 ready to produce the crop of flies which once more lays its eggs in 

 the first crop of clover. 



In appearance these flies are very frail little creatures, brown- 

 ish in color and very small, being only a little more than one-eighth 

 of an inch long. They swarm about the clover-heads during the 

 egg-laying season, but are not often observed because of their small 

 size and dull color. Usually the presence of the midge is unsus- 

 pected until after threshing time, when the tiny pink or salmon 

 colored larvae are found mixed with the threshed out clover seed. 

 Sometimes as much as one-fourth or one-third of the product is made 

 up of tiny maggots, which if not understood are very alarming to 

 the farmer, who suspects them of having designs on his seed. All 

 suspicion of wrong doing is unfounded, however, since all the harm 

 was already done before the clover was cut, the maggots being pow- 

 erless to injure the dry, hard seed. 



As already stated, the development of the second crop of clover 

 flowers and the development of the second generation of midges have 

 to occur simultaneously in order for the young seeds to be in just 

 the right condition for food at the time when the young maggots 

 hatch out from the eggs. This is likely to occur if the first crop is 

 cut during the time when the flowers are turning brown. If, on the 

 other hand, we cut the first crop just as the color is beginning to ap- 



